1. Field of the Invention
The present invention relates generally to a check valve and an aquarium siphon employing same, and more particularly, to such a check valve that includes a flapper valve having a unique geometry that allows it to conform to a tubular body when the valve is in an open position and which is configured to form a seal with the body when the valve is in the closed position.
2. Description of the Prior Art
A check valve is a device included between sections of conduit through which fluid flows which enables the fluid to flow in one direction while restricting or preventing its flow in an opposite direction. Such valves are commonly used in many types of plumbing and pneumatic systems for restricting fluid flow in a preselected direction. Although check valves of virtually all shapes and sizes are available, in general the valves are relatively large with reference to the dimensions of the conduit and interfere to some degree with flow in the desired flow direction.
A particular application of a check valve is found in a siphon system for an aquarium tank. As disclosed in U.S. Pat. No. 3,771,544, entitled "Aquarium Siphons" by Tibor Horvath, a siphon tube assembly is employed in the aquarium tank and serves to remove water from the tank into a filter tank hung over the edge of the aquarium tank. In the siphon tube assembly a check valve is attached to the short end of a siphon tube for disposition in the filter tank. The check valve is a relatively complex structure that is expensive to manufacture and does not respond immediately to prevent fluid flow in a reverse direction.